Classification tree based information retrieval scheme

• US 6,363,375 B1
• Filed: 09/30/1999
• Issued: 03/26/2002
• Est. Priority Date: 09/30/1998
• Status: Expired due to Fees

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Hayashi, Tsuyoshi, Kato, Kinji, Hoshino, Takashi, Hasegawa, Yasushi, Kishimoto, Giichi
• Primary Examiner(s): Coby, Frantz
• Application Number:
  US09/410,146
• Time in Patent Office: 908 Days
• Field of Search: 707/103, 707/2, 707/3, 707/4, 707/5
• US Class Current: 1/1
• CPC Class Codes: G06F 16/3323 using document space presentation or visualization, e.g. category, hierarchy or range presentation and selection
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99935 Query augmenting and refining, e.g. inexact access
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure

Abstract

An information retrieval scheme using classification trees with respect to a plurality of information sources connected to a network is disclosed, where each classification tree having a hierarchical structure defined in terms of entries. In the information retrieval apparatus, classification tree class information for each classification tree class defined among entries constituting each classification tree is managed, where each classification tree class information indicating retrieval condition parameters for each classification tree class. Then, the information retrieval is controlled by receiving from a user a retrieval request indicating a retrieval target entry that was obtained by the user by tracing the classification trees, generating retrieval commands with respect to selected information sources among said plurality of information sources by referring to each classification tree class information corresponding to the retrieval target entry that is managed by the class definition unit, obtaining a retrieval result of a retrieval with respect to the selected information sources using the retrieval commands, and returning the retrieval result to the user.

Claims

1. An information retrieval apparatus using classification trees with respect to a plurality of information sources connected to a network, each classification tree having a hierarchical structure defined in terms of entries, the apparatus comprising:

a class definition unit for managing classification tree class information for each classification tree class defined among entries constituting each classification tree, each classification tree class information indicating retrieval condition parameters for each classification tree class; and

an information retrieval control unit for receiving from a user a retrieval request indicating a retrieval target entry that was obtained by the user by tracing the classification trees, generating retrieval commands with respect to selected information sources among said plurality of information sources by referring to each classification tree class information corresponding to the retrieval target entry that is managed by the class definition unit, obtaining a retrieval result of a retrieval with respect to the selected information sources using the retrieval commands, and returning the retrieval result to the user.

2. The apparatus of claim 1, wherein each classification tree class information indicates the retrieval condition parameters in terms of retrieval condition items and attributes of each classification tree class from which specific values of the retrieval condition items can be obtained, which are to be used in specifying retrieval conditions to be indicated by the retrieval commands.

3. The apparatus of claim 2, wherein each classification tree class information indicates the retrieval condition parameters also in terms of an operator for specifying a relationship between each retrieval condition item and a specific value obtained from a corresponding attribute of each classification tree class, which is to be used in specifying each retrieval condition.

4. The apparatus of claim 2, wherein each classification tree class information indicates the retrieval condition parameters also in terms of an operator for specifying a connecting relationship among a plurality of retrieval conditions to be indicated by each retrieval command.

5. The apparatus of claim 2, wherein the retrieval request also indicates retrieval items that are to be retrieved from the information sources, and the information retrieval control unit selects those information sources which are compatible with both the retrieval items indicated by the retrieval request and the retrieval condition items indicated by each classification tree class information of each classification tree class corresponding to the retrieval target entry as the selected information sources.

6. The apparatus of claim 5, wherein the class definition unit also manages information source class information for each information source class defined among said plurality of information sources, each information source class information indicating retrieval items that are retrievable from each information source class, and the information retrieval control unit selects the selected information sources by referring to each information source class information managed by the class definition unit.

7. The apparatus of claim 1, wherein the information retrieval control unit incorporates a retrieval condition specified by the retrieval request received from the user into the retrieval commands with respect to the selected information sources.

8. The apparatus of claim 1, further comprising a classification tree retrieval unit for carrying out a retrieval with respect to the classification trees for the retrieval target entry under a control of the information retrieval control unit.

9. The apparatus of claim 1, further comprising an information source retrieval unit for carrying out the retrieval with respect to the selected information sources under a control of the information retrieval control unit.

10. The apparatus of claim 1, further comprising a class definition registration unit for registering, correcting, or deleting each classification tree class information to be managed by the class definition unit.

11. The apparatus of claim 1, wherein the information retrieval apparatus is provided as a server connected with a user terminal device operated by the user through the network.

12. The apparatus of claim 1, wherein the information retrieval apparatus is provided as a part of a client device to be operated by the user in a client-server system while the classification trees are provided by at least one directory server in the client-server system.

13. The apparatus of claim 12, wherein each directory server manages at least one classification tree by storing at least a location information of each content stored in a corresponding information source.

14. The apparatus of claim 13, wherein each directory server retrieves the location information of a requested content upon receiving the retrieval request issued by the client device, and returns the location information of the requested content to the client device, such that the client device obtains a desired content from the corresponding information source according to the location information returned in response to the retrieval request.

15. The apparatus of claim 13, wherein each directory server manages said at least one classification tree by storing a location, access, and attribute information containing the location information of each content stored in the corresponding information source in a prescribed management structure.

16. The apparatus of claim 15, wherein the location, access, and attribute information is given in terms of an entry name of each content, a type indicating a storing format of each content, a subtype indicating a type of each content, the location information of each content, access information of each content that is necessary in accessing each content besides the location information, and attribute information of each content.

17. A method of information retrieval using classification trees with respect to a plurality of information sources connected to a network, each classification tree having a hierarchical structure defined in terms of entries, the method comprising the step of:

managing classification tree class information for each classification tree class defined among entries constituting each classification tree, each classification tree class information indicating retrieval condition parameters for each classification tree class; and

controlling an information retrieval by receiving from a user a retrieval request indicating a retrieval target entry that was obtained by the user by tracing the classification trees, generating retrieval commands with respect to selected information sources among said plurality of information sources by referring to each classification tree class information corresponding to the retrieval target entry that is managed by the managing step, obtaining a retrieval result of a retrieval with respect to the selected information sources using the retrieval commands, and returning the retrieval result to the user.

18. The method of claim 17, wherein each classification tree class information indicates the retrieval condition parameters in terms of retrieval condition items and attributes of each classification tree class from which specific values of the retrieval condition items can be obtained, which are to be used in specifying retrieval conditions to be indicated by the retrieval commands.

19. The method of claim 18, wherein each classification tree class information indicates the retrieval condition parameters also in terms of an operator for specifying a relationship between each retrieval condition item and a specific value obtained from a corresponding attribute of each classification tree class, which is to be used in specifying each retrieval condition.

20. The method of claim 18, wherein each classification tree class information indicates the retrieval condition parameters also in terms of an operator for specifying a connecting relationship among a plurality of retrieval conditions to be indicated by each retrieval command.

21. The method of claim 18, wherein the retrieval request also indicates retrieval items that are to be retrieved from the information sources, and the controlling step selects those information sources which are compatible with both the retrieval items indicated by the retrieval request and the retrieval condition items indicated by each classification tree class information of each classification tree class corresponding to the retrieval target entry as the selected information sources.

22. The method of claim 21, wherein the managing step also manages information source class information for each information source class defined among said plurality of information sources, each information source class information indicating retrieval items that are retrievable from each information source class, and the controlling step selects the selected information sources by referring to each information source class information managed by the managing step.

23. The method of claim 17, wherein the controlling step incorporates a retrieval condition specified by the retrieval request received from the user into the retrieval commands with respect to the selected information sources.

24. The method of claim 17, further comprising the step of carrying out a retrieval with respect to the classification trees for the retrieval target entry under a control of the controlling step.

25. The method of claim 17, further comprising the step of carrying out the retrieval with respect to the selected information sources under a control of the controlling step.

26. The method of claim 17, further comprising the step of registering, correcting, or deleting each classification tree class information to be managed by the managing step.

27. The method of claim 17, wherein the managing step and the controlling step are carried out by a server connected with a user terminal device operated by the user through the network.

28. The method of claim 17, wherein the managing step and the controlling step are carried out by a client device to be operated by the user in a client-server system while the classification trees are provided by at least one directory server in the client-server system.

29. The method of claim 28, further comprising the step of managing at least one classification tree at each directory server by storing at least a location information of each content stored in a corresponding information source.

30. The method of claim 29, further comprising the step of retrieving the location information of a requested content upon receiving the retrieval request issued by the client device, and returning the location information of the requested content to the client device, at each directory server, such that the client device obtains a desired content from the corresponding information source according to the location information returned in response to the retrieval request.

31. The method of claim 29, further comprising the step of managing said at least one classification tree at each directory server by storing a location, access, and attribute information containing the location information of each content stored in the corresponding information source in a prescribed management structure.

32. The method of claim 31, wherein the location, access, and attribute information is given in terms of an entry name of each content, a type indicating a storing format of each content, a subtype indicating a type of each content, the location information of each content, access information of each content that is necessary in accessing each content besides the location information, and attribute information of each content.

33. A computer usable medium having computer readable program code means embodied therein for causing a computer to function as an information retrieval apparatus using classification trees with respect to a plurality of information sources connected to a network, each classification tree having a hierarchical structure defined in terms of entries, the computer readable program code means includes:

first computer readable program code means for causing said computer to manage classification tree class information for each classification tree class defined among entries constituting each classification tree, each classification tree class information indicating retrieval condition parameters for each classification tree class; and

second computer readable program code means for causing said computer to control an information retrieval by receiving from a user a retrieval request indicating a retrieval target entry that was obtained by the user by tracing the classification trees, generating retrieval commands with respect to selected information sources among said plurality of information sources by referring to each classification tree class information corresponding to the retrieval target entry that is managed by the first computer readable program code means, obtaining a retrieval result of a retrieval with respect to the selected information sources using the retrieval commands, and returning the retrieval result to the user.

34. The computer usable medium of claim 33, wherein each classification tree class information indicates the retrieval condition parameters in terms of retrieval condition items and attributes of each classification tree class from which specific values of the retrieval condition items can be obtained, which are to be used in specifying retrieval conditions to be indicated by the retrieval commands.

35. The computer usable medium of claim 34, wherein each classification tree class information indicates the retrieval condition parameters also in terms of an operator for specifying a relationship between each retrieval condition item and a specific value obtained from a corresponding attribute of each classification tree class, which is to be used in specifying each retrieval condition.

36. The computer usable medium of claim 34, wherein each classification tree class information indicates the retrieval condition parameters also in terms of an operator for specifying a connecting relationship among a plurality of retrieval conditions to be indicated by each retrieval command.

37. The computer usable medium of claim 34, wherein the retrieval request also indicates retrieval items that are to be retrieved from the information sources, and the second computer readable program code means selects those information sources which are compatible with both the retrieval items indicated by the retrieval request and the retrieval condition items indicated by each classification tree class information of each classification tree class corresponding to the retrieval target entry as the selected information sources.

38. The computer usable medium of claim 37, wherein the first computer readable program code meas also manages information source class information for each information source class defined among said plurality of information sources, each information source class information indicating retrieval items that are retrievable from each information source class, and the second computer readable program code means selects the selected information sources by referring to each information source class information managed by the first computer readable program code means.

39. The computer usable medium of claim 33, wherein the second computer readable program code means incorporates a retrieval condition specified by the retrieval request received from the user into the retrieval commands with respect to the selected information sources.

40. The computer usable medium of claim 33, further comprising third computer readable program code means for causing said computer to carry out a retrieval with respect to the classification trees for the retrieval target entry under a control of the second computer readable program code means.

41. The computer usable medium of claim 33, further comprising third computer readable program code means for causing said computer to carry out the retrieval with respect to the selected information sources under a control of the second computer readable program code means.

42. The computer usable medium of claim 33, further comprising third computer readable program code means for causing said computer to register, correct, or delete each classification tree class information to be managed by the first computer readable program code means.

43. The computer usable medium of claim 33, wherein the information retrieval computer usable medium is provided as a server connected with a user terminal device operated by the user through the network.

44. The computer usable medium of claim 33, wherein the information retrieval computer usable medium is provided as a part of a client device to be operated by the user in a client-server system while the classification trees are provided by at least one directory server in the client-server system.

45. The computer usable medium of claim 44, wherein each directory server manages at least one classification tree by storing at least a location information of each content stored in a corresponding information source.

46. The computer usable medium of claim 45, wherein each directory server retrieves the location information of a requested content upon receiving the retrieval request issued by the client device, and returns the location information of the requested content to the client device, such that the client device obtains a desired content from the corresponding information source according to the location information returned in response to the retrieval request.

47. The computer usable medium of claim 45, wherein each directory server manages said at least one classification tree by storing a location, access, and attribute information containing the location information of each content stored in the corresponding information source in a prescribed management structure.

48. The computer usable medium of claim 47, wherein the location, access, and attribute information is given in terms of an entry name of each content, a type indicating a storing format of each content, a subtype indicating a type of each content, the location information of each content, access information of each content that is necessary in accessing each content besides the location information, and attribute information of each content.